Binary switch for an optical wavelength router

Abstract

An apparatus and method for routing optical signals between a pair of input ports and a pair of output ports is provided. An optical switching arrangement adapted to shift among at least two distinct optical configurations is provided for directing the optical signals. In the first configuration, the optical signal from the first (second) input port is directed to the first (second) output port. In the second configuration, the optical signal from the first input port is discarded and the optical signal from the second input port is directed to the first output port.

What is claimed is:  
     
       1. An optical routing apparatus for directing a first optical signal and a second optical signal, the optical routing apparatus comprising: 
       (a) a first input port configured to provide the first optical signal;  
       (b) a second input port configured to provide the second optical signal;  
       (c) a first output port configured to receive one of the first and second optical signals;  
       (d) a second output port configured to receive the second optical signal; and  
       (e) an optical switching arrangement adapted to shift among at least two distinct optical configurations, the optical switching arrangement comprising at least one fixed mirror and at least one rotatable mirror,  
       wherein in a first of such optical configurations, the first optical signal follows a first optical path to the first output port and the second optical signal follows a second optical path to the second output port, and  
       wherein in a second of such optical configurations, the second optical signal follows a third optical path to the first output port and the first optical signal is lost,  
       each of such first, second, and third optical paths being defined by the optical switching arrangement.  
     
     
       2. The optical routing apparatus according to  claim 1  wherein the optical switching arrangement comprises two fixed mirrors and two rotatable mirrors, the first optical configuration being defined by a first position for the two rotatable mirrors and the second optical configuration being defined by a second position for the two rotatable mirrors. 
     
     
       3. The optical routing apparatus according to  claim 2  wherein each of the first, second, and third optical paths comprises a reflection off one of the two fixed mirrors and a reflection off one of the two rotatable mirrors. 
     
     
       4. The optical routing apparatus according to  claim 1  wherein the optical switching arrangement comprises at least four fixed mirrors and a single rotatable mirror, the first and second optical configurations being defined by two different positions of the single rotatable mirror. 
     
     
       5. The optical routing apparatus according to  claim 4 , 
       wherein the first optical path comprises a reflection off a first of the four fixed mirrors, a reflection off the single rotatable mirror when it is in a first position, and a reflection off a second of the four fixed mirrors,  
       wherein the second optical path comprises a reflection off a third of the four fixed mirrors, a reflection off the single rotatable mirror when it is in its first position, and a reflection off a fourth of the four fixed mirrors, and  
       wherein the third optical path comprises a reflection off the third fixed mirror, a reflection off the single rotatable mirror when it is in a second position, and a reflection off the second fixed mirror.  
     
     
       6. The optical routing apparatus according to  claim 4  wherein the input and output ports are staggered with respect to each other so that the path lengths of the first, second, and third optical paths are substantially equal. 
     
     
       7. The optical routing apparatus according to  claim 4  wherein 
       (i) the input and output ports are unstaggered, with adjacent input and output ports separated from each other in the approximate ratios 1.77:1.28:1.00; and  
       (ii) the four fixed mirrors are inclined with respect to a perpendicular in the ratio 45°°1.5 δ:45°+0.5 δ:45°−0.5 δ: 45°−1.5 δ, where δ is an angle by which the two different positions of the single rotatable mirror differ.  
     
     
       8. The optical routing apparatus according to  claim 1  wherein the optical switching arrangement comprises a fixed mirror having a focus and a single rotatable mirror positioned at the focus, the first and second optical configurations being defined by two different positions of the single rotatable mirror. 
     
     
       9. The optical routing apparatus according to  claim 8  wherein the fixed mirror is a composite mirror. 
     
     
       10. The optical routing apparatus according to  claim 8  wherein the fixed mirror has the shape of a portion of a rotated conic section. 
     
     
       11. The optical routing apparatus according to  claim 8  wherein the input and output ports are staggered with respect to each other so that the path lengths of the first, second, and third optical paths are substantially equal. 
     
     
       12. The optical routing apparatus according to  claim 1  wherein one of the first and second input ports is separated from one of the first and second output ports by a confocal length of one of the first and second optical signals. 
     
     
       13. The optical routing apparatus according to  claim 12  wherein each of the input and output ports is comprised by an optical fiber, and wherein at least one of such optical fibers is flattened. 
     
     
       14. The optical routing apparatus according to  claim 13  wherein each such optical fiber comprises a core and a cladding layer surrounding the core, and wherein the cladding layer of the flattened optical fiber is shaved. 
     
     
       15. An optical routing apparatus for directing a first or second optical signal, the optical routing apparatus comprising: 
       (a) a first input port configured to provide the first optical signal;  
       (b) a second input port configured to provide the second optical signal;  
       (c) a first output port configured to receive the first optical signal;  
       (d) a second output port configured to receive the first or second optical signals; and  
       (e) an optical switching arrangement adapted to shift among at least three distinct optical configurations, wherein the optical switching arrangement comprises a fixed mirror and a single rotatable mirror, the at least three distinct optical configurations being defined by three different positions of the single rotatable mirror,  
       wherein in a first of such optical configurations, the first optical signal follows a first optical path to the second output port,  
       wherein in a second of such optical configurations, the first optical signal follows a second optical path to the first output port, and  
       wherein in a third of such optical configurations, the second optical signal follows a third optical path to the second output port and the first optical signal is lost.  
     
     
       16. The optical routing apparatus according to  claim 15  wherein the fixed mirror comprises at least three fixed mirrors. 
     
     
       17. The optical routing apparatus according to  claim 16 , 
       wherein the first optical path comprises a reflection off the single rotatable mirror when it is in a first position and a reflection off a first of the three fixed mirrors,  
       wherein the second optical path comprises a reflection off the single rotatable mirror when it is in a second position and a reflection off a second of the three fixed mirrors, and  
       wherein the third optical path comprises a reflection off a third of the three fixed mirrors, a reflection off the single rotatable mirror when it is in a third position, and a reflection off the first fixed mirror.  
     
     
       18. The optical routing apparatus according to  claim 16  wherein the input and output ports are staggered with respect to each other so that the path lengths of the first, second, and third optical paths are substantially equal. 
     
     
       19. The optical routing apparatus according to  claim 15  wherein the fixed mirror has a focus with the single rotatable mirror positioned at the focus. 
     
     
       20. The optical routing apparatus according to  claim 19  wherein the fixed mirror is a composite mirror. 
     
     
       21. The optical routing apparatus according to  claim 19  wherein the fixed mirror has the shape of a portion of a rotated conic section. 
     
     
       22. The optical routing apparatus according to  claim 19  wherein the input and output ports are staggered with respect to each other so that the path lengths of the first, second, and third optical paths are substantially equal. 
     
     
       23. A method for directing a first optical signal and a second optical signal, the method comprising: 
       (a) providing the first optical signal from a first input port;  
       (b) providing the second optical signal from a second input port; and  
       (c) operating an optical switching arrangement to route the first and second optical signals, the optical switching arrangement being adapted to shift among at least two distinct optical configurations,  
       wherein in a first of such optical configurations, the first optical signal follows a first optical path to a first output port and the second optical signal follows a second optical path to a second output port, and  
       wherein in a second of such optical configurations, the second optical signal follows a third optical path to the first output port and the first optical signal is lost,  
       each of such first, second, and third optical paths being defined by the optical switching arrangement.  
     
     
       24. The method according to wherein the optical switching arrangement comprises at least one fixed mirror and at least one rotatable mirror. 
     
     
       25. The method according to  claim 24  wherein the optical switching arrangement comprises two fixed mirrors and two rotatable mirrors, the first optical configuration being defined by a first position for the two rotatable mirrors and the second optical configuration being defined by a second position for the two rotatable mirrors. 
     
     
       26. The method according to  claim 25  wherein each of the first, second, and third optical paths comprises a reflection off one of the two fixed mirrors and a reflection off one of the two rotatable mirrors. 
     
     
       27. The method according to  claim 24  wherein the optical switching arrangement comprises at least four fixed mirrors and a single rotatable mirror, the first and second optical configurations being defined by two different positions of the single rotatable mirror. 
     
     
       28. The method according to  claim 27 , 
       wherein the first optical path comprises a reflection off a first of the four fixed mirrors, a reflection off the single rotatable mirror when it is in a first position, and a reflection off a second of the four fixed mirrors,  
       wherein the second optical path comprises a reflection off a third of the four fixed mirrors, a reflection off the single rotatable mirror when it is in its first position, and a reflection off a fourth of the four fixed mirrors, and  
       wherein the third optical path comprises a reflection off the third fixed mirror, a reflection off the single rotatable mirror when it is in a second position, and a reflection off the second fixed mirror.  
     
     
       29. The method according to  claim 27  further comprising equalizing the path lengths of the first, second, and third optical paths. 
     
     
       30. The method according to  claim 27  wherein 
       (i) the input and output ports are unstaggered, with adjacent input and output ports separated from each other in the approximate ratios 1.77:1.28:1.00; and  
       (ii) the four fixed mirrors are inclined with respect to a perpendicular in the ratio 45°+1.5 δ:45°+0.5 δ:45°−0.5 δ:45°−1.5 δ, where δ is an angle by which the two different positions of the single rotatable mirror differ.  
     
     
       31. The method according to  claim 24  wherein the optical switching arrangement comprises a fixed mirror having a focus and a single rotatable mirror positioned at the focus, the first and second optical configurations being defined by two different positions of the single rotatable mirror. 
     
     
       32. The method according to  claim 31  wherein the fixed mirror is a composite mirror. 
     
     
       33. The method according to  claim 31  wherein the fixed mirror has the shape of a portion of a rotated conic section. 
     
     
       34. The method according to  claim 31  further comprising equalizing the path lengths of the first, second, and third optical paths. 
     
     
       35. The method according to  claim 23  wherein one of the first and second input ports is separated from one of the first and second output ports by a confocal length of one of the first and second optical signals. 
     
     
       36. The method according to  claim 35  wherein each of the input and output ports is comprised by an optical fiber, and wherein at least one of such optical fibers is flattened. 
     
     
       37. The method according to  claim 36  wherein each such optical fiber comprises a core and a cladding layer surrounding the core, and wherein the cladding layer of the flattened optical fiber is shaved. 
     
     
       38. A method for directing a first or second optical signal, the method comprising: 
       (a) providing the first optical signal from a first input port;  
       (b) providing the second optical signal from a second input port; and  
       (c) operating an optical switching arrangement to route the first and second optical signals, the optical switching arrangement being adapted to shift among at least three distinct optical configurations,  
       wherein in a first of such optical configurations, the first optical signal follows a first optical path to a second output port,  
       wherein in a second of such optical configurations, the first optical signal follows a second optical path to a first output port, and  
       wherein in a third of such optical configurations, the second optical signal follows a third optical path to the second output port and the first optical signal is lost.  
     
     
       39. The method according to  claim 38  wherein the optical switching arrangement comprises at least three fixed mirrors and a single rotatable mirror, the at least three distinct optical configurations being defined by three different positions of the single rotatable mirror. 
     
     
       40. The method according to  claim 39 , 
       wherein the first optical path comprises a reflection off the single rotatable mirror when it is in a first position and a reflection off a first of the three fixed mirrors,  
       wherein the second optical path comprises a reflection off the single rotatable mirror when it is in a second position and a reflection off a second of the three fixed mirrors, and  
       wherein the third optical path comprises a reflection off a third of the three fixed mirrors, a reflection off the single rotatable mirror when it is in a third position, and a reflection off the first fixed mirror.  
     
     
       41. The method according to  claim 39  further comprising equalizing the path lengths of the first, second, and third optical paths. 
     
     
       42. The method according to  claim 38  wherein the optical switching arrangement comprises a fixed mirror having a focus and a single rotatable mirror positioned at the focus, the at least three distinct optical configurations being defined by three different positions of the single rotatable mirror. 
     
     
       43. The method according to  claim 42  wherein the fixed mirror is a composite mirror. 
     
     
       44. The method according to  claim 42  wherein the fixed mirror has the shape of a portion of a rotated conic section. 
     
     
       45. The method according to  claim 42  comprising equalizing the path lengths of the first, second, and third optical paths. 
     
     
       46. The optical routing apparatus according to  claim 15  wherein, in the first of such optical configurations, the second optical signal is lost. 
     
     
       47. The optical routing apparatus according to  claim 46  wherein, in the second of such optical configurations, the second optical signal is lost. 
     
     
       48. The optical routing apparatus according to  claim 15  wherein, in e second of such optical configurations, the second optical signal is lost. 
     
     
       49. The method according to  claim 38  wherein, in the first of such optical configurations, the second optical signal is lost. 
     
     
       50. The method according to  claim 49  wherein, in the second of such optical configurations, the second optical signal is lost. 
     
     
       51. The method according to  claim 38  wherein, in the second of such optical configurations, the second optical signal is lost.